Selection of Breeding Habitat by the Thrush Nightingale Luscinia luscinia and Its Position in Bird Communities

Abstract

Certain factors which appear to be decisive in habitat selection by breeding Thrush Nightingales are set out. This species favours deciduous coppices which are usually low and shady. Some dense thickets providing good shelter are always present in the territories. A proportion of bare ground without field vegatation is also important because the species feeds mostly on the ground. The small coppices where territories are established occur in open environments, near water or fields; this improves the audibility of the birds song. The position of the Thrush Nightingale in the bird community is also presented. It belongs to the guild of ground feeders, but unilke most other species of this guild is strongly adapted for foraging inside woodlands. On the other hand, it is also partly able to utilize other zones of vegatation. It can sometimes forage in field vegetation, on branches and boughs of trees, or even in the air. Its main diet consists of insects, mostly Lepidopteran larvae. In terms of habitat requirements and morphological similarities, the Thrush Nightingale has only two potential competitors, the Robin Erithacus rubecula L. and the Redwing Turdus iliacus L. However, the competition between these species seems usually to be weak. The effect of man on habitats is presumably the most important reason for population fluctuations of the Thrush Nightingale in Finland.